condition mean min max ZT0-3 4.4 4.4 4.4 ZT4-7 5.5 5.5 5.5 ZT8-11 40.400000000000006 40.400000000000006 40.400000000000006 ZT12-15 34.15 34.15 34.15 ZT16-19 27.049999999999997 27.049999999999997 27.049999999999997 ZT20-23 16.1 16.1 16.1